Rainy Day Science: Ten Indoor Experiments for Kids

When it’s pouring and the kids are climbing the walls, science is a good bet. Here are ten indoor experiments, each with something to see and a question to answer.

Oobleck. Cornstarch and water make a goo that acts like both a solid and a liquid. Is oobleck a solid or a liquid?
Lava lamp. Oil, water, colouring and a fizzy tablet make blobs rise and fall. Why do the blobs in a lava lamp go up and down?
Frost on a can. Ice and salt make a can frost over. Can you make frost in a can?
Cloud in a jar. Hot water, ice and a bit of smoke make a cloud (grown-up handles heat and matches). How does a cloud form?
Crystal garden. Grow salt, Epsom salt and sugar crystals over a week. How do crystals grow?
Secret messages. Baking soda ink and a grape-juice reveal. How do spies write secret messages?
Light a bulb. One battery, one wire, one bulb. Can you light a bulb with one wire?
Rainbow in a glass. Sunlight or a flashlight through water. Where do rainbows come from?
Balloon rocket. Run a string across the room and launch a balloon. How does a rocket push itself into space?
Paper plane test. Fold two designs and measure three throws each. What makes a paper plane fly farthest?

Keep the mess in check

Put everything on a tray or a baking sheet.
Use old towels and a bucket for cleanup.
Wear an old shirt or apron.
Do oobleck and lava lamps over a sink or a plastic tablecloth.

Make it a science session

Before each one, ask, “What do you think will happen?” After, ask, “What did you see? Why do you think that happened?” You don’t need to know the answer. Say, “Let’s find out.”

Safety

Adults handle hot water and matches. Don’t taste experiments, check for allergies and keep small parts away from toddlers. See our kitchen science safety rules.

Plan ahead

Keep a rainy day box with cornstarch, food colouring, vinegar, baking soda, a few cups and a notebook, so you’re always ready. Browse more at science experiments for kids. Sign up for three lessons free.